Swap my 42RE for a 6 or 8 speed auto
12-16-2014, 09:03 PM
#1
Newbie
Thread Starter
Join Date: Sep 2014
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
Swap my 42RE for a 6 or 8 speed auto
Has anyone swapped a 42re tranny to a 65rfe or 845re. Not even sure it can be done. Trying to find ways to get better gas milage and was told to get a different tranny. Thanks
12-17-2014, 07:45 AM
#4
CF Veteran
Join Date: Feb 2010
Location: Oroville, CA
Posts: 12,367
Likes: 0
Received 19 Likes
on
18 Posts
Year: 1995
Model: Grand Cherokee
Engine: 4.0 with all of the noise and clatter
For the cost of the transmission alone you can buy a lot of gas. You don't drive a Jeep for the great gas mileage, that is what an economy car is for. Swapping in a new transmission may seem like a simple bolt in job, but it's not. Getting it to bolt in is not even half the battle, there are computer issues that need to be addressed. The transmission, labor, and other needed parts would cost about the same as a nice used Toyota Camry.
12-19-2014, 01:42 AM
#5
CF Veteran
Join Date: Jun 2011
Location: Louisville,KY
Posts: 8,014
Likes: 0
Received 14 Likes
on
14 Posts
Model: Cherokee
With it not being a bolt in your looking 3 grand probably after everything.3 grand can buy you a used car easy on gas.Now even if you do the swap you won't see a monster gain in mpg maybe 5mpg in the real world.Not sure what year grand you have or the engine but both the 4.0 and the 5.2 are from the 60s with almost no upgrades but efi pretty much.A 4x4 will never get good gas mileage and the aerodynamics of the zj and wj are kinda a brick on wheels.
12-19-2014, 03:15 AM
#6
Old fart with a wrench
No only are they bricks on wheels, the drive train with 2 live axles is the heaviest there is. My WJ 4.0 weighs 3980 lbs registration weight, most of which is the axles and transfer case. All those gears moving, weither under power or not, create a lot of frictional drag. All that powered by 190 hp doesn't get you much fuel mileage. AND they have the aerodynamics of a falling brick, flat side on.
The only way to get better fuel mileage is to lighten it up and decrease it's frontal cross section. That ain't happening with a 4x4.
The only way to get better fuel mileage is to lighten it up and decrease it's frontal cross section. That ain't happening with a 4x4.
Thread
Thread Starter
Forum
Replies
Last Post
Programbo
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
21
09-26-2015 11:32 AM
jeeplover45
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
4
09-04-2015 06:44 AM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)